git.oblomov.eu Git - linux-2.6/blob - fs/dlm/rcom.c

   1 /******************************************************************************
   2 *******************************************************************************
   3 **
   4 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
   5 **  Copyright (C) 2005-2008 Red Hat, Inc.  All rights reserved.
   6 **
   7 **  This copyrighted material is made available to anyone wishing to use,
   8 **  modify, copy, or redistribute it subject to the terms and conditions
   9 **  of the GNU General Public License v.2.
  10 **
  11 *******************************************************************************
  12 ******************************************************************************/
  13
  14 #include "dlm_internal.h"
  15 #include "lockspace.h"
  16 #include "member.h"
  17 #include "lowcomms.h"
  18 #include "midcomms.h"
  19 #include "rcom.h"
  20 #include "recover.h"
  21 #include "dir.h"
  22 #include "config.h"
  23 #include "memory.h"
  24 #include "lock.h"
  25 #include "util.h"
  26
  27
  28 static int rcom_response(struct dlm_ls *ls)
  29 {
  30         return test_bit(LSFL_RCOM_READY, &ls->ls_flags);
  31 }
  32
  33 static int create_rcom(struct dlm_ls *ls, int to_nodeid, int type, int len,
  34                        struct dlm_rcom **rc_ret, struct dlm_mhandle **mh_ret)
  35 {
  36         struct dlm_rcom *rc;
  37         struct dlm_mhandle *mh;
  38         char *mb;
  39         int mb_len = sizeof(struct dlm_rcom) + len;
  40
  41         mh = dlm_lowcomms_get_buffer(to_nodeid, mb_len, ls->ls_allocation, &mb);
  42         if (!mh) {
  43                 log_print("create_rcom to %d type %d len %d ENOBUFS",
  44                           to_nodeid, type, len);
  45                 return -ENOBUFS;
  46         }
  47         memset(mb, 0, mb_len);
  48
  49         rc = (struct dlm_rcom *) mb;
  50
  51         rc->rc_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
  52         rc->rc_header.h_lockspace = ls->ls_global_id;
  53         rc->rc_header.h_nodeid = dlm_our_nodeid();
  54         rc->rc_header.h_length = mb_len;
  55         rc->rc_header.h_cmd = DLM_RCOM;
  56
  57         rc->rc_type = type;
  58
  59         spin_lock(&ls->ls_recover_lock);
  60         rc->rc_seq = ls->ls_recover_seq;
  61         spin_unlock(&ls->ls_recover_lock);
  62
  63         *mh_ret = mh;
  64         *rc_ret = rc;
  65         return 0;
  66 }
  67
  68 static void send_rcom(struct dlm_ls *ls, struct dlm_mhandle *mh,
  69                       struct dlm_rcom *rc)
  70 {
  71         dlm_rcom_out(rc);
  72         dlm_lowcomms_commit_buffer(mh);
  73 }
  74
  75 /* When replying to a status request, a node also sends back its
  76    configuration values.  The requesting node then checks that the remote
  77    node is configured the same way as itself. */
  78
  79 static void make_config(struct dlm_ls *ls, struct rcom_config *rf)
  80 {
  81         rf->rf_lvblen = cpu_to_le32(ls->ls_lvblen);
  82         rf->rf_lsflags = cpu_to_le32(ls->ls_exflags);
  83 }
  84
  85 static int check_config(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid)
  86 {
  87         struct rcom_config *rf = (struct rcom_config *) rc->rc_buf;
  88         size_t conf_size = sizeof(struct dlm_rcom) + sizeof(struct rcom_config);
  89
  90         if ((rc->rc_header.h_version & 0xFFFF0000) != DLM_HEADER_MAJOR) {
  91                 log_error(ls, "version mismatch: %x nodeid %d: %x",
  92                           DLM_HEADER_MAJOR | DLM_HEADER_MINOR, nodeid,
  93                           rc->rc_header.h_version);
  94                 return -EPROTO;
  95         }
  96
  97         if (rc->rc_header.h_length < conf_size) {
  98                 log_error(ls, "config too short: %d nodeid %d",
  99                           rc->rc_header.h_length, nodeid);
 100                 return -EPROTO;
 101         }
 102
 103         if (le32_to_cpu(rf->rf_lvblen) != ls->ls_lvblen ||
 104             le32_to_cpu(rf->rf_lsflags) != ls->ls_exflags) {
 105                 log_error(ls, "config mismatch: %d,%x nodeid %d: %d,%x",
 106                           ls->ls_lvblen, ls->ls_exflags, nodeid,
 107                           le32_to_cpu(rf->rf_lvblen),
 108                           le32_to_cpu(rf->rf_lsflags));
 109                 return -EPROTO;
 110         }
 111         return 0;
 112 }
 113
 114 static void allow_sync_reply(struct dlm_ls *ls, uint64_t *new_seq)
 115 {
 116         spin_lock(&ls->ls_rcom_spin);
 117         *new_seq = ++ls->ls_rcom_seq;
 118         set_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
 119         spin_unlock(&ls->ls_rcom_spin);
 120 }
 121
 122 static void disallow_sync_reply(struct dlm_ls *ls)
 123 {
 124         spin_lock(&ls->ls_rcom_spin);
 125         clear_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
 126         clear_bit(LSFL_RCOM_READY, &ls->ls_flags);
 127         spin_unlock(&ls->ls_rcom_spin);
 128 }
 129
 130 int dlm_rcom_status(struct dlm_ls *ls, int nodeid)
 131 {
 132         struct dlm_rcom *rc;
 133         struct dlm_mhandle *mh;
 134         int error = 0;
 135
 136         ls->ls_recover_nodeid = nodeid;
 137
 138         if (nodeid == dlm_our_nodeid()) {
 139                 rc = ls->ls_recover_buf;
 140                 rc->rc_result = dlm_recover_status(ls);
 141                 goto out;
 142         }
 143
 144         error = create_rcom(ls, nodeid, DLM_RCOM_STATUS, 0, &rc, &mh);
 145         if (error)
 146                 goto out;
 147
 148         allow_sync_reply(ls, &rc->rc_id);
 149         memset(ls->ls_recover_buf, 0, dlm_config.ci_buffer_size);
 150
 151         send_rcom(ls, mh, rc);
 152
 153         error = dlm_wait_function(ls, &rcom_response);
 154         disallow_sync_reply(ls);
 155         if (error)
 156                 goto out;
 157
 158         rc = ls->ls_recover_buf;
 159
 160         if (rc->rc_result == -ESRCH) {
 161                 /* we pretend the remote lockspace exists with 0 status */
 162                 log_debug(ls, "remote node %d not ready", nodeid);
 163                 rc->rc_result = 0;
 164         } else
 165                 error = check_config(ls, rc, nodeid);
 166         /* the caller looks at rc_result for the remote recovery status */
 167  out:
 168         return error;
 169 }
 170
 171 static void receive_rcom_status(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 172 {
 173         struct dlm_rcom *rc;
 174         struct dlm_mhandle *mh;
 175         int error, nodeid = rc_in->rc_header.h_nodeid;
 176
 177         error = create_rcom(ls, nodeid, DLM_RCOM_STATUS_REPLY,
 178                             sizeof(struct rcom_config), &rc, &mh);
 179         if (error)
 180                 return;
 181         rc->rc_id = rc_in->rc_id;
 182         rc->rc_seq_reply = rc_in->rc_seq;
 183         rc->rc_result = dlm_recover_status(ls);
 184         make_config(ls, (struct rcom_config *) rc->rc_buf);
 185
 186         send_rcom(ls, mh, rc);
 187 }
 188
 189 static void receive_sync_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 190 {
 191         spin_lock(&ls->ls_rcom_spin);
 192         if (!test_bit(LSFL_RCOM_WAIT, &ls->ls_flags) ||
 193             rc_in->rc_id != ls->ls_rcom_seq) {
 194                 log_debug(ls, "reject reply %d from %d seq %llx expect %llx",
 195                           rc_in->rc_type, rc_in->rc_header.h_nodeid,
 196                           (unsigned long long)rc_in->rc_id,
 197                           (unsigned long long)ls->ls_rcom_seq);
 198                 goto out;
 199         }
 200         memcpy(ls->ls_recover_buf, rc_in, rc_in->rc_header.h_length);
 201         set_bit(LSFL_RCOM_READY, &ls->ls_flags);
 202         clear_bit(LSFL_RCOM_WAIT, &ls->ls_flags);
 203         wake_up(&ls->ls_wait_general);
 204  out:
 205         spin_unlock(&ls->ls_rcom_spin);
 206 }
 207
 208 int dlm_rcom_names(struct dlm_ls *ls, int nodeid, char *last_name, int last_len)
 209 {
 210         struct dlm_rcom *rc;
 211         struct dlm_mhandle *mh;
 212         int error = 0;
 213         int max_size = dlm_config.ci_buffer_size - sizeof(struct dlm_rcom);
 214
 215         ls->ls_recover_nodeid = nodeid;
 216
 217         if (nodeid == dlm_our_nodeid()) {
 218                 ls->ls_recover_buf->rc_header.h_length =
 219                         dlm_config.ci_buffer_size;
 220                 dlm_copy_master_names(ls, last_name, last_len,
 221                                       ls->ls_recover_buf->rc_buf,
 222                                       max_size, nodeid);
 223                 goto out;
 224         }
 225
 226         error = create_rcom(ls, nodeid, DLM_RCOM_NAMES, last_len, &rc, &mh);
 227         if (error)
 228                 goto out;
 229         memcpy(rc->rc_buf, last_name, last_len);
 230
 231         allow_sync_reply(ls, &rc->rc_id);
 232         memset(ls->ls_recover_buf, 0, dlm_config.ci_buffer_size);
 233
 234         send_rcom(ls, mh, rc);
 235
 236         error = dlm_wait_function(ls, &rcom_response);
 237         disallow_sync_reply(ls);
 238  out:
 239         return error;
 240 }
 241
 242 static void receive_rcom_names(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 243 {
 244         struct dlm_rcom *rc;
 245         struct dlm_mhandle *mh;
 246         int error, inlen, outlen, nodeid;
 247
 248         nodeid = rc_in->rc_header.h_nodeid;
 249         inlen = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
 250         outlen = dlm_config.ci_buffer_size - sizeof(struct dlm_rcom);
 251
 252         error = create_rcom(ls, nodeid, DLM_RCOM_NAMES_REPLY, outlen, &rc, &mh);
 253         if (error)
 254                 return;
 255         rc->rc_id = rc_in->rc_id;
 256         rc->rc_seq_reply = rc_in->rc_seq;
 257
 258         dlm_copy_master_names(ls, rc_in->rc_buf, inlen, rc->rc_buf, outlen,
 259                               nodeid);
 260         send_rcom(ls, mh, rc);
 261 }
 262
 263 int dlm_send_rcom_lookup(struct dlm_rsb *r, int dir_nodeid)
 264 {
 265         struct dlm_rcom *rc;
 266         struct dlm_mhandle *mh;
 267         struct dlm_ls *ls = r->res_ls;
 268         int error;
 269
 270         error = create_rcom(ls, dir_nodeid, DLM_RCOM_LOOKUP, r->res_length,
 271                             &rc, &mh);
 272         if (error)
 273                 goto out;
 274         memcpy(rc->rc_buf, r->res_name, r->res_length);
 275         rc->rc_id = (unsigned long) r;
 276
 277         send_rcom(ls, mh, rc);
 278  out:
 279         return error;
 280 }
 281
 282 static void receive_rcom_lookup(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 283 {
 284         struct dlm_rcom *rc;
 285         struct dlm_mhandle *mh;
 286         int error, ret_nodeid, nodeid = rc_in->rc_header.h_nodeid;
 287         int len = rc_in->rc_header.h_length - sizeof(struct dlm_rcom);
 288
 289         error = create_rcom(ls, nodeid, DLM_RCOM_LOOKUP_REPLY, 0, &rc, &mh);
 290         if (error)
 291                 return;
 292
 293         error = dlm_dir_lookup(ls, nodeid, rc_in->rc_buf, len, &ret_nodeid);
 294         if (error)
 295                 ret_nodeid = error;
 296         rc->rc_result = ret_nodeid;
 297         rc->rc_id = rc_in->rc_id;
 298         rc->rc_seq_reply = rc_in->rc_seq;
 299
 300         send_rcom(ls, mh, rc);
 301 }
 302
 303 static void receive_rcom_lookup_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 304 {
 305         dlm_recover_master_reply(ls, rc_in);
 306 }
 307
 308 static void pack_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb,
 309                            struct rcom_lock *rl)
 310 {
 311         memset(rl, 0, sizeof(*rl));
 312
 313         rl->rl_ownpid = cpu_to_le32(lkb->lkb_ownpid);
 314         rl->rl_lkid = cpu_to_le32(lkb->lkb_id);
 315         rl->rl_exflags = cpu_to_le32(lkb->lkb_exflags);
 316         rl->rl_flags = cpu_to_le32(lkb->lkb_flags);
 317         rl->rl_lvbseq = cpu_to_le32(lkb->lkb_lvbseq);
 318         rl->rl_rqmode = lkb->lkb_rqmode;
 319         rl->rl_grmode = lkb->lkb_grmode;
 320         rl->rl_status = lkb->lkb_status;
 321         rl->rl_wait_type = cpu_to_le16(lkb->lkb_wait_type);
 322
 323         if (lkb->lkb_bastfn)
 324                 rl->rl_asts |= AST_BAST;
 325         if (lkb->lkb_astfn)
 326                 rl->rl_asts |= AST_COMP;
 327
 328         rl->rl_namelen = cpu_to_le16(r->res_length);
 329         memcpy(rl->rl_name, r->res_name, r->res_length);
 330
 331         /* FIXME: might we have an lvb without DLM_LKF_VALBLK set ?
 332            If so, receive_rcom_lock_args() won't take this copy. */
 333
 334         if (lkb->lkb_lvbptr)
 335                 memcpy(rl->rl_lvb, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
 336 }
 337
 338 int dlm_send_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
 339 {
 340         struct dlm_ls *ls = r->res_ls;
 341         struct dlm_rcom *rc;
 342         struct dlm_mhandle *mh;
 343         struct rcom_lock *rl;
 344         int error, len = sizeof(struct rcom_lock);
 345
 346         if (lkb->lkb_lvbptr)
 347                 len += ls->ls_lvblen;
 348
 349         error = create_rcom(ls, r->res_nodeid, DLM_RCOM_LOCK, len, &rc, &mh);
 350         if (error)
 351                 goto out;
 352
 353         rl = (struct rcom_lock *) rc->rc_buf;
 354         pack_rcom_lock(r, lkb, rl);
 355         rc->rc_id = (unsigned long) r;
 356
 357         send_rcom(ls, mh, rc);
 358  out:
 359         return error;
 360 }
 361
 362 /* needs at least dlm_rcom + rcom_lock */
 363 static void receive_rcom_lock(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 364 {
 365         struct dlm_rcom *rc;
 366         struct dlm_mhandle *mh;
 367         int error, nodeid = rc_in->rc_header.h_nodeid;
 368
 369         dlm_recover_master_copy(ls, rc_in);
 370
 371         error = create_rcom(ls, nodeid, DLM_RCOM_LOCK_REPLY,
 372                             sizeof(struct rcom_lock), &rc, &mh);
 373         if (error)
 374                 return;
 375
 376         /* We send back the same rcom_lock struct we received, but
 377            dlm_recover_master_copy() has filled in rl_remid and rl_result */
 378
 379         memcpy(rc->rc_buf, rc_in->rc_buf, sizeof(struct rcom_lock));
 380         rc->rc_id = rc_in->rc_id;
 381         rc->rc_seq_reply = rc_in->rc_seq;
 382
 383         send_rcom(ls, mh, rc);
 384 }
 385
 386 /* If the lockspace doesn't exist then still send a status message
 387    back; it's possible that it just doesn't have its global_id yet. */
 388
 389 int dlm_send_ls_not_ready(int nodeid, struct dlm_rcom *rc_in)
 390 {
 391         struct dlm_rcom *rc;
 392         struct rcom_config *rf;
 393         struct dlm_mhandle *mh;
 394         char *mb;
 395         int mb_len = sizeof(struct dlm_rcom) + sizeof(struct rcom_config);
 396
 397         mh = dlm_lowcomms_get_buffer(nodeid, mb_len, GFP_NOFS, &mb);
 398         if (!mh)
 399                 return -ENOBUFS;
 400         memset(mb, 0, mb_len);
 401
 402         rc = (struct dlm_rcom *) mb;
 403
 404         rc->rc_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
 405         rc->rc_header.h_lockspace = rc_in->rc_header.h_lockspace;
 406         rc->rc_header.h_nodeid = dlm_our_nodeid();
 407         rc->rc_header.h_length = mb_len;
 408         rc->rc_header.h_cmd = DLM_RCOM;
 409
 410         rc->rc_type = DLM_RCOM_STATUS_REPLY;
 411         rc->rc_id = rc_in->rc_id;
 412         rc->rc_seq_reply = rc_in->rc_seq;
 413         rc->rc_result = -ESRCH;
 414
 415         rf = (struct rcom_config *) rc->rc_buf;
 416         rf->rf_lvblen = cpu_to_le32(~0U);
 417
 418         dlm_rcom_out(rc);
 419         dlm_lowcomms_commit_buffer(mh);
 420
 421         return 0;
 422 }
 423
 424 static int is_old_reply(struct dlm_ls *ls, struct dlm_rcom *rc)
 425 {
 426         uint64_t seq;
 427         int rv = 0;
 428
 429         switch (rc->rc_type) {
 430         case DLM_RCOM_STATUS_REPLY:
 431         case DLM_RCOM_NAMES_REPLY:
 432         case DLM_RCOM_LOOKUP_REPLY:
 433         case DLM_RCOM_LOCK_REPLY:
 434                 spin_lock(&ls->ls_recover_lock);
 435                 seq = ls->ls_recover_seq;
 436                 spin_unlock(&ls->ls_recover_lock);
 437                 if (rc->rc_seq_reply != seq) {
 438                         log_debug(ls, "ignoring old reply %x from %d "
 439                                       "seq_reply %llx expect %llx",
 440                                       rc->rc_type, rc->rc_header.h_nodeid,
 441                                       (unsigned long long)rc->rc_seq_reply,
 442                                       (unsigned long long)seq);
 443                         rv = 1;
 444                 }
 445         }
 446         return rv;
 447 }
 448
 449 /* Called by dlm_recv; corresponds to dlm_receive_message() but special
 450    recovery-only comms are sent through here. */
 451
 452 void dlm_receive_rcom(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid)
 453 {
 454         int lock_size = sizeof(struct dlm_rcom) + sizeof(struct rcom_lock);
 455
 456         if (dlm_recovery_stopped(ls) && (rc->rc_type != DLM_RCOM_STATUS)) {
 457                 log_debug(ls, "ignoring recovery message %x from %d",
 458                           rc->rc_type, nodeid);
 459                 goto out;
 460         }
 461
 462         if (is_old_reply(ls, rc))
 463                 goto out;
 464
 465         switch (rc->rc_type) {
 466         case DLM_RCOM_STATUS:
 467                 receive_rcom_status(ls, rc);
 468                 break;
 469
 470         case DLM_RCOM_NAMES:
 471                 receive_rcom_names(ls, rc);
 472                 break;
 473
 474         case DLM_RCOM_LOOKUP:
 475                 receive_rcom_lookup(ls, rc);
 476                 break;
 477
 478         case DLM_RCOM_LOCK:
 479                 if (rc->rc_header.h_length < lock_size)
 480                         goto Eshort;
 481                 receive_rcom_lock(ls, rc);
 482                 break;
 483
 484         case DLM_RCOM_STATUS_REPLY:
 485                 receive_sync_reply(ls, rc);
 486                 break;
 487
 488         case DLM_RCOM_NAMES_REPLY:
 489                 receive_sync_reply(ls, rc);
 490                 break;
 491
 492         case DLM_RCOM_LOOKUP_REPLY:
 493                 receive_rcom_lookup_reply(ls, rc);
 494                 break;
 495
 496         case DLM_RCOM_LOCK_REPLY:
 497                 if (rc->rc_header.h_length < lock_size)
 498                         goto Eshort;
 499                 dlm_recover_process_copy(ls, rc);
 500                 break;
 501
 502         default:
 503                 log_error(ls, "receive_rcom bad type %d", rc->rc_type);
 504         }
 505 out:
 506         return;
 507 Eshort:
 508         log_error(ls, "recovery message %x from %d is too short",
 509                           rc->rc_type, nodeid);
 510 }
 511